This invention relates to discerning terrestrial targets from the perspective of an aircraft. The invention more specifically relates to digital processing of factors related to target detection by a sensor on an in-flight aircraft and a map of a terrestrial area of interest to generate a visual representation of the probability that earth-based targets will be detectable on segments of lines of communication by the aircraft sensor.
Various techniques exist to detect earth-based targets at a geographic location or on a pathway, roadway or waterway from an in-flight aircraft. For example, high resolution cameras and other sensors, e.g., infrared sensors, radar, etc., may be used to determine if an earth-based target is present at a particular location. Assuming that the aircraft sensor is within its targeting range, atmospheric conditions are acceptable, and a direct line of sight is present between the aircraft and the terrestrial target, it generally follows that the target is likely to be detected. However, a variety of practical considerations complicate the determination of whether a target can be determined to be present. For example, the altitude of the aircraft can significantly affect this determination. Although higher altitudes provide more direct lines of sight over more terrestrial surface area, higher altitudes also mean the sensors used for targeting must operate at a greater distance from the area of interest. This brings into question whether the sensitivity of the sensor is sufficient at the larger distances (higher altitudes) to be able to identify the presence of a target with sufficient probability.
Additionally, the presence of certain geographic features, e.g., mountains, may inhibit a direct line of sight between the airborne sensor and potential target locations depending on the location of the aircraft and area of interest relative to the mountain. Since roadways and/or waterways in mountainous regions are often located at or near valleys, the visibility of these are a function of the position of the aircraft relative to mountain peaks adjacent the valleys.
For an airborne observation mission to increase the probability of success of being able to detect a target, it would be desirable to predict in advance of the mission the probabilities of target detection for particular areas of interest, e.g., particular segments of roadways/waterways. Thus, there exists a need to determine, prior to carrying out an observation mission which can be very expensive, the probabilities of target detection by an aircraft for different factors impacting detection possibilities and provide this information in a form easily understood so that a mission planner can adjust the factors to increase the odds of successfully detecting the presence of targets.